Yes, "The Hardy Boys/Nancy Drew Mysteries" TV show was popular during its run in the late 1970s. It capitalized on the popularity of the books and characters and attracted a dedicated fan base.
It was not considered very popular back then. But I like watching it now. They had problems with the actress playing Nancy Drew, Pamela, and so they had to deal with that.
There is one season of "The Hardy Boys/Nancy Drew Mysteries," which aired in 1977-1979.
The Hardy Boys Nancy Drew Mysteries - 1977 is rated/received certificates of: Australia:PG
The Hardy Boys Nancy Drew Mysteries - 1977 was released on: USA: 30 January 1977 Belgium: 20 September 1978
The Hardy Boys Nancy Drew Mysteries - 1977 Wipe-Out 1-11 was released on: USA: 24 April 1977
The Hardy Boys Nancy Drew Mysteries - 1977 A Haunting We Will Go 1-8 was released on: USA: 3 April 1977
The Hardy Boys Nancy Drew Mysteries - 1977 Nancy Drew's Love Match 2-10 was released on: USA: 20 November 1977
Yes
The Hardy Boys Nancy Drew Mysteries - 1977 Game Plan 3-9 was released on: USA: 3 December 1978
The Hardy Boys Nancy Drew Mysteries - 1977 The Disappearing Floor 1-5 was released on: USA: 6 March 1977
The Hardy Boys Nancy Drew Mysteries - 1977 Assault on the Tower 3-3 was released on: USA: 15 October 1978
The Hardy Boys Nancy Drew Mysteries - 1977 Campus Terror 2-22 was released on: USA: 7 May 1978
The Hardy Boys Nancy Drew Mysteries - 1977 Mystery on the Avalanche Express 2-19 was released on: USA: 26 February 1978